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available. These findings include (i) microcytic anemia; (ii) elevated EP level,
especially if higher than 250 mcg/dL (conversely, a normal or minimally elevated
EP level, less than 50 mcg/dL, would make lead encephalopathy caused by
chronic lead paint exposure unlikely); (iii) basophilic stippling of peripheral
erythrocytes or, if feasible, of red blood cell precursors on bone marrow
examination; (iv) glycosuria; (v) aminoaciduria; (vi) radiopaque flecks on
abdominal radiographs; and (vii) dense metaphyseal bands on radiographs of
knees and wrists (lead lines— Fig. 102.11 ).
Abnormalities on examination of cerebrospinal fluid (CSF) are also indicative
of lead encephalopathy, including a lymphocytic pleocytosis, elevated protein
level, and increased pressure.
The treatment of lead poisoning involves relocation of the child to a lead-free
environment, consideration of chelation therapy, and appropriate supportive care.
Symptomatic patients are at risk of developing encephalopathy with subsequent
death or neurologic sequelae. In addition, asymptomatic patients with high BLL
(especially higher than 100 mcg/dL) are also at significant risk for developing
CNS involvement and might require urgent treatment. Routine chelation is not
indicated for children with BLL less than 45 mcg/dL.
The specific chelating drugs commonly used for symptomatic lead intoxication
are edetate calcium disodium (CaNa2 EDTA) and 2,4-dimercaptopropanol
(British Anti-Lewisite [BAL]; Table 102.16 ). Side effects of CaNa2 EDTA
include local reactions at injection sites, fever, hypercalcemia, and renal
dysfunction manifested by rising BUN and abnormal urine sediment with
proteinuria, hematuria, and/or epithelial cells. The major side effects of BAL
include nausea and vomiting, so for the first day or two of BAL therapy, it is
prudent to maintain the patient on IV fluids and clear liquids or nothing by
mouth. BAL is formulated in peanut oil, is given only by IM injection, and also
induces hemolysis in patients with G6PD deficiency. Its use is hazardous if the
patient has severe hepatic dysfunction, and it forms a toxic complex if given
concurrently with iron. Succimer (dimercaptosuccinic acid [DMSA]) has been
approved for pediatric use in cases in which BLL exceeds 45 mcg/dL ( Table

102.16 ). This water-soluble analog of BAL may be taken orally, and several
studies have found such use to be as effective as CaNa2 EDTA given parenterally.